[PATCH AUTOSEL 6.14 053/642] r8169: disable RTL8126 ZRX-DC timeout

Sasha Levin
2025-05-05T22:15:59Z

From: ChunHao Lin <hau@realtek.com>

[ Upstream commit b48688ea3c9ac8d5d910c6e91fb7f80d846581f0 ]

Disable it due to it dose not meet ZRX-DC specification. If it is enabled,
device will exit L1 substate every 100ms. Disable it for saving more power
in L1 substate.

Signed-off-by: ChunHao Lin <hau@realtek.com>
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://patch.msgid.link/20250318083721.4127-3-hau@realtek.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/realtek/r8169_main.c | 27 +++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 5a5eba49c6515..4ead966727734 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -2850,6 +2850,32 @@ static u32 rtl_csi_read(struct rtl8169_private *tp, int addr)
RTL_R32(tp, CSIDR) : ~0;
}

+static void rtl_disable_zrxdc_timeout(struct rtl8169_private *tp)
+{
+ struct pci_dev *pdev = tp->pci_dev;
+ u32 csi;
+ int rc;
+ u8 val;
+
+#define RTL_GEN3_RELATED_OFF 0x0890
+#define RTL_GEN3_ZRXDC_NONCOMPL 0x1
+ if (pdev->cfg_size > RTL_GEN3_RELATED_OFF) {
+ rc = pci_read_config_byte(pdev, RTL_GEN3_RELATED_OFF, &val);
+ if (rc == PCIBIOS_SUCCESSFUL) {
+ val &= ~RTL_GEN3_ZRXDC_NONCOMPL;
+ rc = pci_write_config_byte(pdev, RTL_GEN3_RELATED_OFF,
+ val);
+ if (rc == PCIBIOS_SUCCESSFUL)
+ return;
+ }
+ }
+
+ netdev_notice_once(tp->dev,
+ "No native access to PCI extended config space, falling back to CSI\n");
+ csi = rtl_csi_read(tp, RTL_GEN3_RELATED_OFF);
+ rtl_csi_write(tp, RTL_GEN3_RELATED_OFF, csi & ~RTL_GEN3_ZRXDC_NONCOMPL);
+}
+
static void rtl_set_aspm_entry_latency(struct rtl8169_private *tp, u8 val)
{
struct pci_dev *pdev = tp->pci_dev;
@@ -3822,6 +3848,7 @@ static void rtl_hw_start_8125d(struct rtl8169_private *tp)

static void rtl_hw_start_8126a(struct rtl8169_private *tp)
{
+ rtl_disable_zrxdc_timeout(tp);
rtl_set_def_aspm_entry_latency(tp);
rtl_hw_start_8125_common(tp);
}
--
2.39.5